Flood protection in an age of sea level rise, by gimleteye

The scientists talk about "tipping points", by way of suggesting that sea level rise may be sudden and abrupt depending on the trajectory of Greenland and Antarctica ice melt.

The Washington Post, on 1/29/2008 ("Debate on Climate Shifts to Issue of Irreparable Change", writes:

If either of the two sheets disintegrates, sea level could rise nearly 20 feet in the course of a couple of centuries, swamping the southern third of Florida and Manhattan up to the middle of Greenwich Village.

Twenty feet wouldn't happen all at once. But even a foot at a time; the first indication of sea level rise in Florida will be shattering.

Think about it: in Miami, the tide inches up the sea wall. Still, a foot of sea level rise isn't going to be noticed much. I don't have a clue when it is going to happen, but when it does I predict there will be chaos.

The timing of sea level rise is debatable, but there is a big difference between debatable risk and quantifiable liability.

Confounding the two gives politicians a way to do nothing, or very little, or only what is marginally impacting on profits of campaign contributors: exactly the course taken by the Bush White House.

Whoever the next president is, he or she will face a torrent of objections from imposing costs on industry to drastically reduce emissions of greenhouse gases. Prove it, they'll say. And then when the sea level rises, they'll say--guaranteed--give us flood control.

Government is extraordinarily adept at removing water from land. But the same geology in Florida that make it so easy to drain water--through canals cut in a shallow and porous aquifer--makes it impossible to hold water back. We are not Holland or Venice, Italy.


In the Washington Post, "David Warrilow, who heads science policy on climate change for Britain's Department of Environment, Food and Rural Affairs, said that while the science remains unsettled, his government has decided to take a precautionary approach. He compared consuming massive amounts of fossil fuels to the strategy of the Titanic's crew, who were unable to avoid an iceberg because they were speeding across the Atlantic in hopes of breaking a record. "We know there are icebergs out there, but at the moment we're accelerating toward the tipping point," Warrilow said in an interview. "This is silly. We should be doing the opposite, slowing down whilst we build up our knowledge base."

As far as the effects of sea level rise in Florida are concerned, we have plenty of knowledge. In "Stories of life in South Dade", published in 1912, we get some. The writer, Carl Schumacher, observed some local rock pits, mined to supply road bed material at the time.

These pits would have enough water in them the year around for us to take a swim any day of the year. The water was clear and free of any pollution because there was a constant flow through the coral rock that kept the water filtered and pure... none of these... pits mentioned exists today. But, in the days when they were usable, they were the center of entertainment for a long time.

In other words, by the early 1900's, the canals dug in South Miami Dade had already lowered the water table enough so that the rock pits no longer provided swimming holes.

Today's rock pits in the Lake Belt, today, are massive slashes in the aquifer. They are filled with gangrenous looking fresh water, observable when you fly in and out of Miami International Airport.

The day is coming when the memory of fresh water flowing so purely from the Everglades into rock pits will burn a hole into the public consciousness, filling as it will be, with salt.